Endovascular devices and methods for exploiting intramural space

ABSTRACT

The present disclosure is directed to a device. The device may include a distal shaft defining a central lumen and an orienting element comprising at least one inflatable member. Wherein a first portion of the orienting element extending from the shaft in a first direction and a second portion of the orienting element extending from the shaft in a second direction. Further, wherein the second direction is substantially opposite the first direction.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.12/222,737, filed Aug. 14, 2008, which is a continuation-in-part of PCTInternational Application No. PCT/US2007/024209, filed Nov. 20, 2007,which claims the benefit of U.S. Provisional Application No. 60/964,765,filed Aug. 14, 2007, U.S. Provisional Application No. 60/905,849, filedMar. 9, 2007, and U.S. Provisional Application No. 60/860,416, filedNov. 21, 2006, each of which are herein incorporated by reference intheir entirety.

FIELD OF THE INVENTION

The inventions described herein relate to devices and associated methodsfor the treatment of chronic total occlusions. More particularly, theinventions described herein relate to devices and methods for crossingchronic total occlusions and establishing a pathway blood flow past thechronic total occlusions.

BACKGROUND OF THE INVENTION

Due to age, high cholesterol and other contributing factors, a largepercentage of the population has arterial atherosclerosis that totallyoccludes portions of the patient's vasculature and presents significantrisks to patient health. For example, in the case of a total occlusionof a coronary artery, the result may be painful angina, loss of cardiactissue or patient death. In another example, complete occlusion of thefemoral and/or popliteal arteries in the leg may result in limbthreatening ischemia and limb amputation.

Commonly known endovascular devices and techniques are eitherinefficient (time consuming procedure), have a high risk of perforatinga vessel (poor safety) or fail to cross the occlusion (poor efficacy).Physicians currently have difficulty visualizing the native vessellumen, cannot accurately direct endovascular devices toward thevisualized lumen, or fail to advance devices through the lesion. Bypasssurgery is often the preferred treatment for patients with chronic totalocclusions, but less invasive techniques would be preferred.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a somewhat stylized representation of a human heart. The heartincludes a plurality of coronary arteries, all of which are susceptibleto occlusion.

FIG. 2 is an enlarged view further illustrating a portion of the heartshown in the previous figure. In FIG. 2, a total occlusion is shownwithin a coronary artery.

FIG. 3 is a perspective view of a blood vessel (e.g., a coronaryartery). In FIG. 3, the wall of the blood vessel is shown having threelayers (the intima, the media, and the adventitia).

FIG. 4 is a lateral cross-sectional view of the artery shown in theprevious figure. In FIG. 4, an orienting device is shown disposedbetween the adventitia and the intima of the artery.

FIG. 5 is a longitudinal cross-sectional view of an artery having anocclusion blocking the true lumen.

FIG. 6 is an additional cross-sectional view of the artery shown in theprevious figure. In the embodiment of FIG. 6, a crossing device has beenadvanced over a guidewire so that a distal portion of crossing device isdisposed in proximal segment of the true lumen.

FIG. 7 is a plan view showing an assembly including crossing deviceshown in the previous figure.

FIG. 8 is an additional view of an artery. In the embodiment of FIG. 8,the distal end of the crossing device has been advanced in a distaldirection so that the tip of the crossing device is adjacent anocclusion that is blocking the true lumen of the artery.

FIG. 9 is an additional view of the artery and the crossing device shownin the previous figure. In the embodiment of FIG. 9, the distal end ofthe crossing device has been advanced between the intima and theadventitia of the wall of the artery.

FIG. 10 is an additional view of the artery shown in the previousfigure. In the embodiment of FIG. 10, the crossing device has beenwithdrawn and a guidewire remains in the position formerly occupied bythe crossing device.

FIG. 11 is an additional view of the artery and the guidewire shown inthe previous figure. In the embodiment of FIG. 11, an orienting device100 been advanced over the guidewire.

FIG. 12 is an additional view of the artery and the orienting deviceshown in the previous figure.

FIG. 13 is an additional view showing the orienting device shown in theprevious figure. In the embodiment of FIG. 13 a re-entry device has beenadvanced into a central lumen of the orienting device. A distal end ofthe re-entry device has been advanced through a first aperture of theorienting device and can be seen residing in the true lumen.

FIG. 14 is an enlarged cross-sectional view of the orienting deviceshown in the previous figure.

FIG. 15 is a stylized plan view showing the orienting device shown inthe previous figure.

FIG. 16 is a perspective view of an additional exemplary embodiment ofan orienting device.

FIG. 17 is a plan view showing an additional exemplary orienting device.

FIG. 18 is a stylized perspective view showing a portion of theorienting device shown in the previous figure. For purposes ofillustration, the portion shown in FIG. 18 is created by cutting theorienting device along cutting plane A-A and cutting plane B-B shown inthe previous figure.

FIG. 19 is a stylized cross-sectional view showing the orienting deviceshown in the previous figure. In the embodiment of FIG. 20, an orientingelement of the orienting device is assuming a deployed shape.

FIG. 20 is an additional stylized cross-sectional view showing theorienting device shown in the previous figure. In the embodiment of FIG.20, an orienting element of the orienting device is assuming a generallycollapsed shape.

FIG. 21 is a plan view showing an additional exemplary orienting device.

BRIEF SUMMARY

Described herein are devices and methods employed to exploit thevascular wall of a vascular lumen for the purpose of bypassing a totalocclusion of an artery. Exploitation of a vascular wall may involve thepassage of an endovascular device into and out of said wall which iscommonly and interchangeable described as false lumen access, intramuralaccess, submedial access or in the case of this disclosure, subintimalaccess.

In one aspect, the present disclosure is directed to a device. Thedevice may include a distal shaft defining a central lumen and anorienting element comprising at least one inflatable member. Wherein afirst portion of the orienting element extending from the shaft in afirst direction and a second portion of the orienting element extendingfrom the shaft in a second direction. Further, wherein the seconddirection is substantially opposite the first direction.

In another aspect, the present disclosure is directed to a device. Thedevice may include a distal shaft defining a central lumen and anorienting element comprising a first inflatable member and a secondinflatable member. Wherein the first inflatable member extending fromthe shaft in a first direction and the second inflatable memberextending from the shaft in a second direction. Further, wherein thesecond direction is substantially opposite the first direction.

In yet another aspect, the present disclosure is directed to a method.The method may include providing a device comprising a distal shaft andan orienting element, and positioning the orienting element of thedevice between an occlusion and an adventitia of a blood vessel. Themethod may further include inflating an inflatable member of theorienting element to orient the device relative to a true lumen of theblood vessel, and advancing a re-entry device through a lumen defined bythe device. The method may still further include advancing a distal endof a re-entry device through an aperture of the device, and wherein theaperture is substantially orthogonal to a plane defined by the orientingelement.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

The following detailed description should be read with reference to thedrawings in which similar elements in different drawings are numberedthe same. The drawings, which are not necessarily to scale, depictillustrative embodiments and are not intended to limit the scope of theinvention.

FIG. 1 is a somewhat stylized representation of a human heart 50. Heart50 includes a plurality of coronary arteries 52, all of which aresusceptible to occlusion. Under certain physiological circumstances andgiven sufficient time, some occlusions may become total or complete,such as total occlusion 36. As used herein, the terms total occlusionand complete occlusion are intended to refer to the same or similardegree of occlusion with some possible variation in the age of theocclusion. Generally, a total occlusion refers to a vascular lumen thatis ninety percent or more functionally occluded in cross-sectional area,rendering it with little to no blood flow therethrough and making itdifficult or impossible to pass a conventional guide wire therethrough.Also generally, the older the total occlusion the more organized theocclusive material will be and the more fibrous and calcified it willbecome. According to one accepted clinical definition, a total occlusionis considered chronic if it is greater than two weeks old from symptomonset.

FIG. 2 is an enlarged view further illustrating a portion of heart 50shown in the previous figure. In FIG. 2, a total occlusion 36 is shownwithin a coronary artery 52. Generally, the proximal segment 32 ofartery 52 (i.e., the portion of artery 52 proximal of total occlusion36) may be easily accessed using endovascular devices and has adequateblood flow to supply the surrounding cardiac muscle. The distal segment34 of artery 52 (i.e., the portion of artery 52 distal of totalocclusion 36) is not easily accessed with interventional devices and hassignificantly reduced blood flow as compared to proximal segment 32.

FIG. 3 is a perspective view of an artery 20 having a wall 22. In FIG.3, wall 22 of artery 20 is shown having three layers. The outermostlayer of wall 22 is the adventitia 24 and the innermost layer of wall 22is the intima 26. Intima 26 defines a true lumen 30 of artery 20. Thetissues extending between intima 26 and adventitia 24 may becollectively referred to as the media 28. For purposes of illustration,intima 26, media 28 and adventitia 24 are each shown as a singlehomogenous layer in FIG. 3. In the human body, however, the intima andthe media each comprise a number of sub-layers. The transition betweenthe external most portion of the intima and the internal most portion ofthe media is sometimes referred to as the subintimal space 40.

With reference to FIG. 3, it will be appreciated that the subintimalspace 40 has a generally annular shape with its radial center at thecenter of the true lumen. Some of the devices and methods discussed inthis detailed description may take advantage of the position andgeometry of the subintimal space 40 relative to the true lumen of theblood vessel. For example, some orienting devices described herein maybe adapted to orient themselves within that space. Once the orientationof the orienting device is established, the orienting device may be usedto direct a re-entry device toward the true lumen.

FIG. 4 is a lateral cross-sectional view of artery 20 shown in theprevious figure. In FIG. 4, an orienting device 100 is shown disposedbetween adventitia 24 and intima 26 of artery 20. Orienting device 100comprises a distal shaft 102 having an outer wall 128 defining a centrallumen 104. Orienting device 100 comprises an orienting element 120 thatis coupled to distal shaft 102.

In the embodiment of FIG. 4, orienting element 120 comprises aninflatable member 126. The top of inflatable member 126 may be fixed todistal shaft 102, for example, at a first interface 190A. The bottom ofinflatable member 126 may be fixed to distal shaft 102, for example, ata second interface 190B.

Orienting element 120 comprises a first portion 106 and a second portion108. First portion 106 of orienting element 120 extends in a firstdirection away from distal shaft 102. Second portion 108 of orientingelement 120 extends away from distal shaft 102 in a second directionthat is generally opposite the first direction.

Distal shaft 102 defines a first aperture 130 and a second aperture 132.First aperture 130 extends in a third direction through distal shaft102. A second aperture 132 extends through distal shaft 102 in a forthdirection that is generally opposite the third direction. The firstaperture 130 and second aperture 132 are generally oriented at a rightangle to a tangent plane TP. In FIG. 4, tangent plane TP is tangent tosubintimal space 40.

When inflatable member 126 of orienting element 120 is inflated betweenadventitia 24 and intima 26 of artery 20 orienting device 100 willorient itself within artery 20 so that either first aperture 130 orsecond aperture 132 opens toward a true lumen of the artery. In theembodiment of FIG. 4, orienting device 100 has been positioned so thatfirst aperture 130 opens toward intima 26 of artery 20 and secondaperture 132 opens toward adventitia 24. In FIG. 4, a re-entry device 80is shown extending through first aperture 130 and intima 26. A distalend of re-entry device 80 is disposed in true lumen 30 of blood vessel20.

When inflatable member 126 is inflated, the number of directions thatfirst aperture 130 and second aperture 132 may be facing is reduced.This may be conceptualized in terms of degrees of freedom. Wheninflatable member 126 of orienting element 120 is inflated, the numberof directions that an aperture may be facing is reduced from 360 degreesof freedom to two degrees of freedom, 180 degrees apart. Orientingdevice 100 and re-entry device 80 may be used to establish fluidcommunication between the proximal segment and the distal segment thatare separated by an occlusion. Exemplary methods may be described withreference to FIGS. 5 through 13.

FIG. 5 is a longitudinal cross-sectional view of an artery 20 having anocclusion 36 blocking true lumen 30 thereof. Occlusion 36 divides truelumen 30 into a proximal segment 32 and a distal segment 34. In FIG. 5,a distal portion of a guidewire 60 is shown extending into proximalsegment 32 of true lumen 30. The methods described in this document mayinclude the step of advancing a guidewire to a location proximate anocclusion in a blood vessel. The exemplary methods described in thisdocument may also include the step of advancing guidewire 60 betweenocclusion 36 and adventitia 24 of wall 22. In some cases, however, thenature of the occlusion and the blood vessel will be such that theguidewire is unlikely to advance beyond the occlusion. When this is thecase, the guidewire may be used to guide additional endovascular devicesto a location proximate occlusion 36.

FIG. 6 is an additional cross-sectional view of artery 20 shown in theprevious figure. In the embodiment of FIG. 6, a crossing device 70 hasbeen advanced over guidewire 60 so that a distal portion of crossingdevice 70 is disposed in proximal segment 32 of true lumen 30. Crossingdevice 70 of FIG. 6 comprises a tip 74 that is fixed to a distal end ofa shaft 72. Crossing device 70 may be used in conjunction with a methodfor establishing a channel between proximal segment 32 and distalsegment 34. The methods described in this document may include the stepof advancing a crossing device over a guidewire.

In some useful methods in accordance with the present disclosure,crossing device 70 may be rotated about its longitudinal axis and movedin a direction parallel to its longitudinal axis simultaneously. Whenthis is the case, rotation of crossing device 70 may reduce resistanceto the axial advancement of crossing device 70. These methods takeadvantage of the fact that the kinetic coefficient of friction isusually less than the static coefficient of friction for a givenfrictional interface. Rotating crossing device 70 assures that thecoefficient of friction at the interface between the crossing device andthe surround tissue will be a kinetic coefficient of friction and not astatic coefficient of friction.

FIG. 7 is a plan view showing an assembly including crossing device 70shown in the previous figure. In the embodiment of FIG. 7, a handleassembly 150 is coupled to crossing device 70. In FIG. 7, handleassembly 150 is shown disposed about a proximal portion of a shaft 152of crossing device 70. In FIG. 7, a portion of handle assembly 150 ispositioned between the thumb and forefinger of a left hand LH. A secondportion of handle assembly 150 is disposed between the thumb andforefinger of a right hand RH. With reference to FIG. 7, it will beappreciated that handle assembly 150 is long enough to receive the thumband forefingers of a physician's right and left hands. When this is thecase, a physician can use two hands to rotate handle assembly 150.

Rotation of crossing device 70 can be achieved by rolling handleassembly 150 between the thumb and forefinger of one hand. Two hands mayalso be used to rotate handle assembly 150 as shown in FIG. 7. In someuseful methods, crossing device 70 can be rotated and axially advancedsimultaneously.

In some useful methods in accordance with the present disclosure,crossing device 70 is rotated at a rotational speed of between about 2revolutions per minute and about 200 revolutions per minute. In someparticularly useful methods in accordance with the present disclosure,crossing device 70 is rotated at a rotational speed of between about 50revolutions per minute and about 150 revolutions per minute.

Crossing device 70 may be rotated by hand as depicted in FIG. 7. It isalso contemplated that a mechanical device (e.g., an electric motor) maybe used to rotate crossing device 70. Rotating crossing device 70assures that the coefficient of friction at the interface between thecrossing device and the surround tissue will be a kinetic coefficient offriction and not a static coefficient of friction.

FIG. 8 is an additional longitudinal cross-sectional view of an artery20. In the embodiment of FIG. 8, the distal end of crossing device 70has been advanced in a distal direction so that tip 74 is adjacentocclusion 36. With reference to FIG. 8, it will be appreciated that tip74 has passed beyond intima 26 and is disposed between occlusion 36 andadventitia 24 of artery 20. Some methods described in this document mayinclude the step of advancing a crossing device between an occlusion andthe adventitia of an artery.

FIG. 9 is an additional view of artery 20 and crossing device 70 shownin the previous figure. In the embodiment of FIG. 9, the distal end ofcrossing device 70 has been advanced in an axial direction pastocclusion 36. Methods described herein may include the step of advancinga crossing device beyond an occlusion. In the embodiment of FIG. 9,crossing device has crossed occlusion 36 by advancing between occlusion36 and adventitia 24 of wall 22.

It is to be appreciated that other methods of crossing an occlusion arewithin the spirit and scope of this disclosure. For example, thecrossing device 70 may pass through occlusion 36 while remainingdisposed inside true lumen 30. In FIG. 9, tip 74 of crossing device 70is shown residing between intima 26 and adventitia 24 of artery 20. Astip 74 moves in an axial direction between intima 26 and adventitia 24,tip 74 may cause blunt dissection of the layers forming wall 22 ofartery 20. Alternatively, tip 74 may cause blunt dissection of thematerials comprising the occlusion 36.

In the embodiment of FIG. 9, tip 74 of crossing device 70 is disposedbetween intima 26 and adventitia 24. When this is the case, fluidcommunication between proximal segment 32 and distal segment 34 may beachieved by creating an opening through intima 26. Such an opening maybe created, for example, using a re-entry device and an orienting devicethat directs the advancement of the re-entry device toward intima 26.

FIG. 10 is an additional view of artery 20 shown in the previous figure.In the embodiment of FIG. 10, crossing device 70 has been withdrawn fromtrue lumen 30 of artery 20. With reference to FIG. 10, it will beappreciated that guidewire 60 remains in the position formerly occupiedby crossing device 70.

The position of guidewire 60 shown in FIG. 10 may be achieved usingcrossing device 70. Guidewire 60 may be positioned, for example, byfirst placing crossing device 70 in the position shown in the previousfigure, then advancing guidewire 60 through lumen 122 defined by shaft72 of crossing device 70. Alternately, guidewire 60 may be disposedwithin lumen 122 while crossing device 70 is advanced beyond occlusion36.

With guidewire 60 in the position shown in FIG. 10, guidewire 60 may beused to direct other devices between occlusion 36 and adventitia 24. Forexample, a catheter may be advanced over guidewire 60 until the distalend of the catheter extends between an occlusion and the adventia. Afterreaching this location, the catheter may be used to dilate the tissuesurrounding the catheter. Examples of catheters that may be used todilate tissue include inflatable member catheters and atherectomycatheters.

FIG. 11 is an additional view of artery 20 and guidewire 60 shown in theprevious figure. In the embodiment of FIG. 11, an orienting device 100has been advanced over guidewire 60. Orienting device 100 includes adistal shaft 102 comprising a outer wall 128 defining a central lumen104. A first aperture 130 and a second aperture 132 are also defined byouter wall 128. In the embodiment of FIG. 11, first aperture 130 andsecond aperture 132 are both in fluid communication with central lumen104.

In the embodiment of FIG. 11, orienting device 100 has been positionedso that first aperture 130 opens toward intima 26 of artery 20 andsecond aperture 132 opens toward adventitia 24. In the embodiment ofFIG. 11, first aperture 130 and second aperture 132 are longitudinallyseparated from one another. Orienting device 100 includes a firstradiopaque marker that is located between first aperture 130 and secondaperture 132. A second radiopaque marker of orienting device 100 islocated distally of second aperture 132.

FIG. 12 is an additional view of artery 20 and orienting device 100shown in the previous figure. In the embodiment of FIG. 12, guidewire 60has been withdrawn leaving orienting device 100 in the position shown inFIG. 12. With reference to FIG. 12, it will be appreciated thatorienting device 100 extends beyond occlusion 36. In FIG. 12, occlusion36 is shown blocking true lumen 30. Occlusion 36 divides true lumen 30into a proximal segment 32 and a distal segment 34. When an orientingdevice in accordance with some embodiments disclosed herein is advancedbetween the adventitia and the intima of an artery, the orienting devicemay be used to direct a re-entry device toward true lumen 30. Fluidcommunication between proximal segment 32 and distal segment 34 may beachieved by re-entering the true lumen with the re-entry device.

FIG. 13 is an additional view of artery 20 and orienting device 100shown in the previous figure. In the embodiment of FIG. 13, a re-entrydevice 80 has been advanced into central lumen 104 of orienting device100. A distal end 132 of re-entry device 80 has been advanced throughfirst aperture 130 and can be seen residing in true lumen 30.

After re-entry device 80 is positioned as shown in FIG. 13, orientingdevice 100 may be withdrawn leaving re-entry device 80 in the positionshown in FIG. 13. Devices such as inflatable member angioplastycatheters and atherectomy catheters may then be advanced over re-entrydevice 80. In this way, these devices may be used in conjunction withre-entry device 80 to establish a blood flow path between proximalsegment 32 of true lumen 30 and distal segment 34 of true lumen 30. Thispath allows blood to flow around occlusion 36.

FIG. 14 is an enlarged cross-sectional view of orienting device 100shown in the previous figure. Orienting device 100 includes a distalshaft 102 comprising an outer wall 128 defining a central lumen 104.Outer wall 128 defines a first aperture 130 and a second aperture 132that are both in fluid communication with central lumen 104. In theembodiment of FIG. 14, first aperture 130 extends away from centrallumen 104 in a first direction that is represented by a first arrow AAin FIG. 14. Second aperture 132 extends away from central lumen 104 in asecond direction that is represented by a second arrow AB in FIG. 14. InFIG. 14, first arrow AA and second arrow AB extend in generally oppositedirections. In FIG. 14, first arrow AA and second arrow AB are directedabout 180 degrees away from one another.

In the embodiment of FIG. 14, first aperture 130 and second aperture 132are longitudinally separated from one another. Orienting device 100includes a first radiopaque marker 134A that is located between firstaperture 130 and second aperture 132. A second radiopaque marker 134B oforienting device 100 is located distally of second aperture 132.

A re-entry device 80 is disposed in central lumen 104 of orientingdevice 100. In the embodiment of FIG. 14A, first radiopaque marker 134A,second radiopaque marker 134B and re-entry device 80 comprise radiopaquematerials. Because of the radiopaque nature of their materials ofconstruction, first radiopaque marker 134A, second radiopaque marker134B, and re-entry device 80 will all be visible on a fluoroscopicdisplay during a fluoroscopic procedure. The relative location of theseradiopaque elements on the fluoroscopic display can be used to directthe distal end of re-entry device 80 through a selected aperture inorienting device 100.

FIG. 15 is a stylized plan view showing orienting device 100 shown inthe previous figure. In FIG. 15, a distal portion of re-entry device 80can be seen extending through first aperture 130. First aperture 130 andsecond aperture 132 both fluidly communicate with central lumen 104 oforienting device 100. Orienting device 100 includes a first radiopaquemarker 134A that is located between first aperture 130 and secondaperture 132. A second radiopaque marker 134B of orienting device 100 islocated distally of second aperture 132.

Orienting device 100 comprises an orienting element 120 that is fixed toa distal shaft 102. Orienting element 120 comprises an inflatable member126. When inflatable member 126 of orienting element 120 is inflatedbetween the adventicia and the intima of a blood vessel, orientingdevice 100 will orient itself within the blood vessel so that eitherfirst aperture 130 or second aperture 132 opens toward a true lumen ofthe artery. The physician may select the aperture opening toward thetrue lumen, for example, using the fluoroscopic methods describedherein. The physician may then insert the distal end of re-entry device80 through the selected aperture.

FIG. 16 is a perspective view of an orienting device 200. Orientingdevice 200 comprises a distal shaft 202, a proximal shaft 92 and anintermediate shaft 82 that extends between distal shaft 202 and proximalshaft 92. Orienting device 200 includes an orienting element 220 that iscoupled to a distal shaft 202. In the embodiment of FIG. 21, orientingelement 220 comprises an inflatable member 226 that is fixed to distalshaft 202. Inflatable member 226 may be fixed to distal shaft 202, forexample, at a proximal waist 246A, at a distal waist 246B, at the top ofthe inflatable member 226, and at the bottom of the inflatable member.

Orienting element 220 comprises a first portion 206 and a second portion208. First portion 206 of orienting element 220 extends in a firstdirection away from distal shaft 202. Second portion 208 of orientingelement 220 extends away from distal shaft 202 in a second directionthat is generally opposite the first direction.

A hub 236 is fixed to the proximal end of proximal shaft 92. Hub 236includes a proximal port 238. Proximal port 238 fluidly communicateswith an interior of inflatable member 226 via inflation lumens definedby distal shaft 202, intermediate shaft 82, and proximal shaft 92.Inflatable member 226 may be inflated by injecting an inflation mediainto proximal port 238. Examples of inflation media that may be suitablein some applications include saline, carbon dioxide, or nitrogen. Insome useful embodiments, inflatable member 226, distal shaft 202,intermediate shaft 82, and proximal shaft 92 comprise thermoplasticmaterials. Examples of thermoplastic materials that may be suitable insome applications include Nylon, Pebax, or P.E.T.

A first aperture 230 is disposed on a first side of orienting element220. When inflatable member 226 of orienting element 220 is inflatedbetween the adventicia and the intima of a blood vessel, orientingdevice 200 will orient itself within the blood vessel so that firstaperture 230 either opens toward the true lumen of the artery or opens180 degrees away from the true lumen of the artery. A second aperture isdisposed on a second side of orienting element 220. Second aperture isnot visible in FIG. 16. First aperture 230 is disposed on a first sideof orienting element 220 and the second aperture is disposed on a secondside of orienting element that is generally opposite the first side.

FIG. 17 is a plan view showing an additional exemplary orienting device300. Orienting device 300 of FIG. 17 comprises an orienting element 320coupled to a distal shaft 302. In the embodiment of FIG. 17, orientingelement 320 comprises a first inflatable member 322 and a secondinflatable member 324. In the embodiment of FIG. 17, first inflatablemember 322 and second inflatable member 324 are both formed fromextruded portions of an outer wall 328 of distal shaft 302. Outer wall328 defines a first aperture 330 and a second aperture 332. Withreference to FIG. 17, it will be appreciated that first aperture 330 andsecond aperture 332 are both disposed between first inflatable member322 and second inflatable member 324.

FIG. 18 is a stylized perspective view showing a portion 340 oforienting device 300 shown in the previous figure. Portion 340 iscreated by cutting orienting device 300 along cutting plane A-A andcutting plane B-B shown in the previous figure.

Orienting device 300 comprises an orienting element 320 that is coupledto a distal shaft 302. Orienting element 320 comprises a firstinflatable member 322 and a second inflatable member 324. Firstinflatable member 322 of orienting element 320 extends in a firstdirection away from distal shaft 302. Second inflatable member 324 oforienting element 320 extends away from distal shaft 302 in a seconddirection that is generally opposite the first direction.

With reference to FIG. 18, it will be appreciated that first inflatablemember 322 extends away from outer wall 328 in a first direction that isrepresented by an arrow labeled OD. With continuing reference to FIG.18, it will be appreciated that second inflatable member 324 extends wayfrom distal shaft 302 in a second direction that is generally oppositethe first direction. In FIG. 18, the second direction is represented byan arrow labeled SD.

With reference to FIG. 18, it will be appreciated that an outer wall 328of distal shaft 302 defines a first aperture 330 and a second aperture332. First aperture 330 extends away from central lumen 304 in a thirddirection that is represented by an arrow labeled TD. With continuingreference to FIG. 18, it will be appreciated that second aperture 332extends away from central lumen 304 in a forth direction that isgenerally opposite the third direction. In FIG. 18, the fourth directionis represented by an arrow labeled FD.

With reference to FIG. 18, it will be appreciated that first aperture330 and second aperture 332 are both disposed between first inflatablemember 322 and second inflatable member 324. First aperture 330 andsecond aperture 332 both fluidly communicate with a central lumen 304defined by distal shaft 302. First aperture 330 and second aperture 332are generally oriented at a right angle to a plane P defined by firstinflatable member 322 and second inflatable member 324 of orientingelement 320.

FIG. 19 is a stylized cross-sectional view showing orienting device 300shown in the previous figure. With reference to FIG. 19, it will beappreciated that distal shaft 302 defines a central lumen 304, a firstplanetary lumen 342, a second planetary lumen 344. The planetary lumensare defined in part by an outer wall 328 of distal shaft 302. Outer wall328 also defines a first aperture 330 and a second aperture 332. Firstaperture 330 and second aperture 332 both fluidly communicate withcentral lumen 304.

Orienting device 300 comprises an orienting element 320 that includes afirst inflatable member 322 and a second inflatable member 324. In theembodiment of FIG. 19, first inflatable member 322 is formed of anextruded portion of outer wall 328 of distal shaft 302. First inflatablemember 322 defines an interior that is in fluid communication with firstplanetary lumen 342. In the embodiment of FIG. 19, first inflatablemember 322 and distal shaft 302 are monolithic. As shown in FIG. 19,first inflatable member 322 and outer wall 328 of distal shaft 302 areseamlessly formed from a single piece of material. With reference toFIG. 19, it will be appreciated that second inflatable member 324defines an interior that is in fluid communication with second planetarylumen 344. In the embodiment of FIG. 19, second inflatable member 324comprises an extruded portion of outer wall 328 of distal shaft 302.

One potential advantage of creating an orienting element from amonolithic tube is the elimination of fixation points between theorienting element and catheter shaft thus reducing processing steps andmanufacturing cost. Another potential advantage is the reduction offixation points between the orienting element and catheter shaft whichmay also reduce the distal diameter of the catheter by eliminating areasof overlapping material. Another potential advantage may include thereduction of potential failure points through the elimination offixation points (e.g. thermal or adhesive bonds) between the orientingelement and the catheter shaft.

First inflatable member 322 of orienting element 320 extends in a firstdirection away from distal shaft 302. Second inflatable member 324 oforienting element 320 extends away from distal shaft 302 in a seconddirection that is generally opposite the first direction.

In the embodiment of FIG. 19, orienting element 320 is assuming adeployed shape. Also in the embodiment of FIG. 19, first inflatablemember 322 and second inflatable member 324 are both in a generallyinflated state. With reference to FIG. 19, it will be appreciated thatfirst inflatable member 322 and second inflatable member 324 define aplane P. With continuing reference to FIG. 19, it will be appreciatedthat orienting element 320 has a first width WA and first thickness TA.In the embodiment of FIG. 19, first width WA is greater than firstthickness TA when orienting element 320 is assuming a deployed shape.

In some useful embodiments, an aspect ratio of first width WA to firstthickness TA is greater than about one when orienting element 320 isassuming a deployed shape. In some particularly useful embodiments, theaspect ratio of first width WA to first thickness TA is greater thanabout two when orienting element 320 is assuming a deployed shape. Insome especially useful embodiments, the aspect ratio of first width WAto first thickness TA is greater than about three when orienting element320 is assuming a deployed shape.

FIG. 20 is an additional stylized cross-sectional view showing orientingdevice 300 shown in the previous figure. In the embodiment of FIG. 20,orienting element 320 is assuming a generally collapsed shape and theinflatable members are in a substantially deflated state. When theinflatable members are deflated, orienting element 320 may assumevarious collapsed and/or folded shapes. In the embodiment of FIG. 20,orienting element 320 has a second width WB.

A deployed shape of orienting element 320 is shown with dotted lines inFIG. 20. With reference to FIG. 20, it will be appreciated thatorienting element 320 has a first width WA that is greater than secondwidth WB when orienting element 320 is assuming a deployed shape.

FIG. 21 is a plan view showing an additional exemplary orienting device700. Orienting device 700 of FIG. 21 comprises an orienting element 720coupled to a distal shaft 702. In the embodiment of FIG. 21, orientingelement 720 comprises a first inflatable member 722 and a secondinflatable member 724. In the embodiment of FIG. 21, first inflatablemember 722 and second inflatable member 724 are both formed fromextruded portions of an outer wall 728 of distal shaft 702. Outer wall728 defines a first aperture 730 and a second aperture 732. Withreference to FIG. 21, it will be appreciated that first aperture 730 andsecond aperture 732 are both disposed between first inflatable member722 and second inflatable member 724.

With reference to FIG. 21, it will be appreciated that first inflatablemember 722 has a first length LA and second inflatable member 724 has asecond length LB. In the embodiment of FIG. 21, second length LB isgreater than first length LA. In one useful method, first inflatablemember 722 and second inflatable member 724 are both inflated with aradiopaque inflation media. When this is the case, a physician may usefluoroscopic visualization techniques to determine the orientation oforienting device 700 by observing first inflatable member 722 and secondinflatable member 724 on the fluoroscopic display.

From the foregoing, it will be apparent to those skilled in the art thatthe present invention provides, in exemplary non-limiting embodiments,devices and methods for the treatment of chronic total occlusions.Further, those skilled in the art will recognize that the presentinvention may be manifested in a variety of forms other than thespecific embodiments described and contemplated herein. Accordingly,departures in form and detail may be made without departing from thescope and spirit of the present invention as described in the appendedclaims.

1. A method, comprising: positioning an orienting element mounted on acatheter shaft between an occlusion and an adventitia of a blood vessel;inflating an inflatable member of the orienting element to orient thecatheter shaft relative to a true lumen of the blood vessel; andadvancing a re-entry device through a lumen of the catheter shaft suchthat a distal end of the re-entry device extends out a first aperture ofthe catheter shaft toward the true lumen of the blood vessel; whereinthe first aperture is substantially orthogonal to a plane defined by theorienting element.
 2. The method of claim 1, wherein the catheter shafthas a central longitudinal axis extending parallel to the plane definedby the orienting element.
 3. The method of claim 1, wherein the firstaperture extends through a sidewall of the catheter shaft.
 4. The methodof claim 3, wherein the first aperture is positioned between a firstballoon of the inflatable member and a second balloon of the inflatablemember.
 5. The method of claim 4, wherein the first and second balloonsinflate in generally opposite directions along the plane.
 6. The methodof claim 3, further comprising a second aperture extending through thesidewall of the catheter shaft.
 7. The method of claim 6, wherein thefirst and second apertures are positioned on opposing sides of thecatheter shaft.
 8. The method of claim 6, wherein the first aperture isaxially offset from the second aperture.
 9. The method of claim 1,further comprising advancing the catheter shaft over a guidewire toposition the orienting element between the occlusion and the adventitiaof the blood vessel.
 10. The method of claim 9, wherein the guidewire ispositioned in the lumen of the catheter shaft.
 11. The method of claim10, further comprising: withdrawing the guidewire from the lumen of thecatheter shaft prior to advancing the re-entry device through the lumenof the catheter shaft.
 12. A method, comprising: advancing a catheterincluding a catheter shaft and an inflatable member mounted on distalregion thereof over a guidewire to position the inflatable memberbetween an occlusion and an adventitia of a blood vessel, the catheterincluding a first lateral aperture; inflating the inflatable member toorient the first lateral aperture toward a true lumen of the bloodvessel; and advancing a re-entry device through a lumen of the cathetershaft such that a distal end of the re-entry device extends out thefirst aperture of the catheter toward the true lumen of the bloodvessel.
 13. The method of claim 12, wherein inflating the inflatablemember causes the catheter to rotate about a central longitudinal axisof the catheter.
 14. The method of claim 13, wherein the first apertureextends through a sidewall of the catheter shaft.
 15. The method ofclaim 14, wherein the first aperture is positioned between a firstballoon of the inflatable member and a second balloon of the inflatablemember.
 16. The method of claim 15, wherein the first and secondballoons inflate in generally opposite directions along a plane passingthrough the central longitudinal axis.
 17. The method of claim 15,further comprising a second aperture extending through the sidewall ofthe catheter shaft.
 18. The method of claim 17, wherein the first andsecond apertures are positioned on opposing sides of the catheter shaft.19. The method of claim 18, wherein the first aperture is axially offsetfrom the second aperture.
 20. The method of claim 17, wherein the firstand second apertures both open into the lumen of the catheter shaft.